Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2a0fe914 authored by Yong Ding's avatar Yong Ding Committed by Chris Ball
Browse files

mmc: sdio: fix setting card data bus width as 4-bit 



SDIO_CCCR_IF[1:0] in SDIO card is used for card data bus width
setting as below:

     00b: 1-bit bus
     01b: Reserved
     10b: 4-bit bus
     11b: 8-bit bus (only for embedded SDIO)

And sdio_enable_wide is for setting data bus width as 4-bit.
But currently, it first reads the register, second OR' 1b with
SDIO_CCCR_IF[1], and then writes it back.

As we can see, this is based on such assumption that the
SDIO_CCCR_IF[0] is always 0. Apparently, this is not right.

Signed-off-by: default avatarYong Ding <yongd@marvell.com>
Acked-by: default avatarPhilip Rakity <prakity@marvell.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 693e5e20

drivers/mmc/core/sdio.c

+6 −0
Original line number Diff line number Diff line
@@ -218,6 +218,12 @@ static int sdio_enable_wide(struct mmc_card *card) 
	if (ret)

		return ret;



	if ((ctrl & SDIO_BUS_WIDTH_MASK) == SDIO_BUS_WIDTH_RESERVED)

		pr_warning("%s: SDIO_CCCR_IF is invalid: 0x%02x\n",

			   mmc_hostname(card->host), ctrl);



	/* set as 4-bit bus width */

	ctrl &= ~SDIO_BUS_WIDTH_MASK;

	ctrl |= SDIO_BUS_WIDTH_4BIT;



	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);

include/linux/mmc/sdio.h

+2 −0
Original line number Diff line number Diff line
@@ -98,7 +98,9 @@ 


#define SDIO_CCCR_IF		0x07	/* bus interface controls */



#define  SDIO_BUS_WIDTH_MASK	0x03	/* data bus width setting */

#define  SDIO_BUS_WIDTH_1BIT	0x00

#define  SDIO_BUS_WIDTH_RESERVED 0x01

#define  SDIO_BUS_WIDTH_4BIT	0x02

#define  SDIO_BUS_ECSI		0x20	/* Enable continuous SPI interrupt */

#define  SDIO_BUS_SCSI		0x40	/* Support continuous SPI interrupt */